G&K Experimental Unit: XVL1456
by VentXekart
Summary: In the year 2063, Persica and a small group of G&K personnel rediscover an old research facility as well as some information about the projects that were being worked on there. One project in particular would lead to the birth of a new model of T-Doll.


The year is 2063, the war between Sangvis Ferri and Griffon & Kryuger and their allies continues on. Battles from the land between the Gynoid infantry units known as T-dolls from both sides. Whilst Sangvis Ferri had the advantage in that their units had energy weapons and smarter AI, Griffon & Kryuger's units had versatility and they were literally linked to whatever firearms they had on hand thanks to the development of the Advanced Statistic Session Tool, more colloquially referred to as the etching tool.

Unfortunately, so far G&K's units have been limited in that the etching tool was primarily used for firearms and energy weapons such as those used by Sangvis Ferri were incompatible with the T-dolls of G&K due to differences of hardware and components. However, that would all change after the discovery of a weapon long thought lost in the late twentieth, early twenty-first century...

* * *

The dry air over the deserts of New Mexico was overwhelming for poor Persica. Despite the Beilan Island Incident and the outbreaks of Eurosky Low-Emission Infectious Disease (ELID) the United States of America managed to persevere even in the face of a pandemic that crippled its northern neighbor; Canada while also doing a significant amount of damage to Mexico, and the Caribbean islands. New Mexico was one of the states that was hardest hit by the pandemic, forcing much of its populace to flee to the North East while refugees from south of the border would have to cautiously traverse the ruins of the state in order to avoid mutants, hostile wildlife, uninhabitable areas of the desert and the collapsing infrastructure.

Even after thirty-years had passed, one could still see the highways clogged with motor vehicles, cities with high-rising towers, and even more rural townships with stores and homes alike were now abandoned and reclaimed by nature.

Persica; a researcher of Important Operation Prototype Manufacturing Company (IOP) more specifically its Research & Development child company 16Lab couldn't help but frown at the sight of what used to be a bustling part of society. She brushed aside her pink hair, her red eyes peering out of the window of the Military Helicopter transporting her all the way here from her research facility to a site of interest...or so the heads of the company claimed.

Last night, when she had once again fell asleep after completing yet another project after twenty-eight hours of work without sleep, she was awoken by an intern who told her that the boys and girls at G&K wanted to speak with her. Despite her disheveled appearance and the fact, she was hoping to get some beauty-sleep she complied. Apparently, one of their echelons was performing a logistics mission down in that area with the focus being on scavenging for scrap metal and parts that could be recycled for later use when they stumbled upon the entrance of an unidentified facility. Instead of sending one of the interns there to take care of things, she was carted into a Humvee and then tossed into a helicopter towards a nearby aircraft carrier before being tossed into yet another helicopter which would take her towards her destination.

She sighed to herself, asking whatever deities in existence would was getting a laugh out of her misfortune (as well as her lack of sleep). But she received no answer. Though now that she thought about it, it wasn't as bad as what poor Kalina at G&K had to deal with. Poor girl was pretty much forced to write combat report after combat report on a near-regular basis. She shuddered at the thought of being forced to do just that.

She was jostled out of her thoughts when she felt the shudder of the helicopter landing. Stretching her stiff limbs like a cat, she stood up and opened the side door, revealing the face of a G&K T-doll, this one being that of a Galil T-doll; she was wearing a brown dress uniform, a black pair of tights on her legs that lead to her brown ankle-high combat boots and an empty holster on her right thigh, a bracelet on the wrist of her right hand, a necklace with a single metal square that went down to the top edge of her white undershirt just above her breasts and finally she was wielding her namesake firearm; an Israeli Military Industries Galil Assault Rifle. Her skin was white, but her eyes and hair were a matching brown and dangling lightly from her ears were a pair of piercings with small jewels on them.

"Doctor Persica?" She asked to which the doctor replied with a long yawn of "Yeah, I'm here..." before following the T-Doll down the hill. After quickly shaking herself awake, she started taking in the surrounding environment with an odd amount of interest. She saw the curve of a road that had obviously seen better days, at the beginning of the curve was an artificial tunnel, this one having long doors that had probably been pulled open manually judging by the tools that laid nearby. At the end of it was a road that lead to a warehouse to the right of it while in front was the path of a hydroelectric dam.

"Is that dam still functional?" She asked Galil, whom replied with a shrugged.

"Sort of, Grizzly and some combat engineers from the US Marines went inside earlier. They say that despite its age it's still in pretty good shape, they just need to get that thing running again and we might be able send some power up North."

"Who owns it?" Persica asked.

"Don't know, we stumbled upon this place a couple of days ago. We've got a bunch of marines and personnel from G&K who've been trying to get inside, but we've had access to the areas outdoors. Maybe you'll have better luck than we did!"

Persica chuckled, "Maybe I will, where are we head?"

A jeep pulled out of the tunnel, this one occupied by a Thompson Sub-Machine gun T-Doll. She has purple hair, red eyes, tinted oval-shaped glasses, and pale white skin. She was wearing a purple fedora with an orange strap around it on the side of her head, a blouse that exposed her midriff and was strapped to her chest by a pair of belts, a lose purple jacket with orange that covered all except her arms which were adorned with leather bracelets and orange gloves. A holster with a pair of extra drums for her namesake, a pair of leather pants that covered her high-heeled boots, a pair of golden headphones hung around her neck, and finally in between her teeth was a fresh cigarette.

"Ay, Galil! The doc here or what?"

"Yeah, can you take us to the entrance?"

"No sweat! Hop on board!"

"Shotgun!" called Galil as she jumped into the passenger seat.

"Aren't ya an assault rifle though?"

Persica snickered, it was bad pun, but it was a well-timed and well-executed on in her opinion. She sat in the back with a suitcase full of equipment in her lap.

"Let's get this over with." Persica said.

"Whateva you say, Doc!"

After a quick U-turn, Thompson drove the jeep back into the tunnel.

* * *

"Alright, we're here!" Thompson said as she pulled over into a parking lot.

Persica stepped out and saw that apart from a few old sandblasted jeeps, a trailer belonging to G&K and of course two military trucks belonging to the Marine Corps there wasn't much to look at until she saw the building. It was obviously man-made being made from concrete, but she could see a set of glass windows on the top of building and a concrete entrance with some sort of security door.

"Has anyone managed to get inside yet?" Persica asked.

The American T-doll snorted.

"Nah, they've been trying to get the damn door open for the past several hours, they said something about it being a biometric scanner or something keeping it locked up tight."

Persica raised an eyebrow. A biometric scanner in a facility like this seemed odd to her, unless they were trying to hide something. Of course, if it was a private and/or federal contractor or a military base then she would understand but...why would a military base have a hydroelectric dam of all things? It just screamed "I'm a target, bomb me motherfuckers!".

She digressed though, deciding to talk to the engineers at the front door.

"Excuse me?"

"Huh?" The combat engineer tilted his head up to her eye-level.

"Oh, you must be the scientist from I-O-P that was called in. I'm Lt. Jackson, I've been trying to get this bastard open for a couple of hours now."

"How come you haven't just blown the door or something?" She asked.

"Well, the captain and those fine gals from the G&K said that they wanted to keep this place intact so...I've been over here trying to bypass this bad boy and let me tell ya; I've never tried hacking a biometric lock and I hope I won't have to do it again."

Persica paused for a second, before dropping her suitcase, unfolding it and pulling out her laptop.

"Mind if I give it a shot?" She asked.

The combat engineer shrugged and stood up.

"Knock yourself out, but I'm telling you there is no way in hell anyone can-"

"Done!"

The engineer turned back to her after she shut her laptop before the front door opened.

"Wha-? Ho-?"

Persica chuckled to herself.

"I used a piece of software I've been working on to bypass biometric locks on Sangvis Fenri T-Dolls. I didn't expect it to work on the door but..." She shrugged.

"Better than nothing, right?"

"Um..." The combat engineer didn't know what to say. Part of him was embarrassed at the fact a scientist managed to do what he's been attempting to do for the past several hours in just a few seconds but on the other hand he felt satisfied that at least he wouldn't have to work on it again.

"I'll...just go inform the captain..."

"You do that." Persica said with a cheeky smile and a two-fingered salute.

The soldier cleared his throat and gave a quick salute, a "Ma'am." before darting off to whomever was in charge.

"Hey, Thompson, Galil! Mind covering me?"

"Sure, Doc!"

"Of course, Doctor."

* * *

Inside a facility long since lost, there was a small cacophony of beeps before a louder one of confirmation rang out, with the front door opening with a soft hydraulic hiss that scattered long-settling dust away.

Thompson and Galil went in first, both of them had their namesake weapons out in the air as they peered into the room. Behind them trailed Persica.

The room itself was a lobby of some sort, with two plant areas to the left and right that had become overgrown and had reached into the ceiling and walls.

In front of them was a circular entrance desk with several desktop computers with several flat screen monitors on it. To the left underneath a deck from the floor above was a waiting area with a table, several chairs and several chairs, while a hallway to the right of that area remained shut with an armored door that said "CONTAINMENT"

Thompson gave a low whistle,

"Damn, how old do you think this place is, Galil?"

The Assault Rifle T-Doll shrugged but she then saw an emblem of the familiar double-helix of DNA but above and below it was text arranged in an unfamiliar phrase.

"Hey, Thompson? Can you read that?" Galil asked pointing her namesake weapon at the symbol.

Thompson straightened her glasses and narrowed her eyes.

"What the hell? It says...Superbus V-Via..."

As she struggled to read the phrase, Persica however rolled her eyes as she plugged her laptop into one of the old desktop computers.

"Galil, Thompson, It's Latin."

"Oh...okay." Thompson muttered only to be interrupted by Galil, "Okay, then what does it mean then?"

Persica rolled her eyes before taking a glance at it before sighing.

"Superbus Via Inscientiae...Basically it means; Arrogance through Ignorance or something like that..." She paused for a minute before looking at it again, "They probably didn't phrase it right now that I look at it."

"Right then..." Thompson said.

Persica narrowed her eyes for a moment, looking at the old desktop computer that her laptop was plugged into before pressing the power button to it.

For a moment nothing happened and then there was a soft whir as long-since-unused hardware came to life.

Immediately the boot-up sequence came up for a moment, the emblem of the old energy-star program ran by the EPA appeared at the top-right corner of the screen as the machine checked for available memory, the CPU speed and the available hard drive space and then going black once again.

Soon though the black screen was populated by text;

 **CONNECTING TO PRIMARY SERVER...**

 **CONNECTING...**

 **ERROR! UNABLE TO CONNECT TO SERVER, RETRY? Y/N?**

Persica narrowed her eyes in annoyance, this either meant that the servers were un-powered or in a worse...debilitated by decades of abandonment or un-use. She was about to call Thompson back until she heard a buzz and a shuddered throughout the building before lights popped on, some of them flickering with a dull electrical buzz. She heard a beep behind her as two unused vending machines came back to life.

Then she then heard a crackle of static behind her as an unused speaker came back to life with the whine of feedback and a buzzing of unintelligent chatter until it spoke.

"SECTOR G POWER ONLINE..." Came the artificial baritone male voice... "SYSTEM REBOOTING..."

"Doc, what's going on?" Thompson asked with suspicious uncertainty in her voice as she raised her namesake weapon just in case.

Persica eased her with a gesture of her hand going downwards, causing the T-Doll to raise an eyebrow at her.

"It's probably some sort of automated announcement system, nothing we need to worry abou-"

Then there was a stutter of electrical chatter before a beep rang through the speakers and the system spoke again;

"HELLO. THE AUTOMATIC DIAGNOSTIC AND ANNOUNCEMENT SYSTEM WELCOMES YOU TO THE BLACK MESA RESEARCH FACILITY. REMEMBER: HAVE A SECURE DAY!"

"Black Mesa?" Galil asked.

Persica on the other hand was grinning like a madwoman.

"Fucking Jackpot!" She yelled.

"Hey, uh, doc... you okay?" Thompson asked bemusedly as the women began typing commands on her laptop with much enthusiasm.

Persica looked up, saw the two T-Dolls expressions before clearing her throat.

"Sorry, I just couldn't help myself. I mean of all the places to end up, it had to be Black Mesa!"

Thompson looked confusedly at Galil who shrugged before she hauled her namesake weapon over her shoulder.

"Okay, I'll bite...what is Black Mesa?"

In literally no time at all, Persica zoomed behind the T-dolls with her hands on their respective shoulders and a grin on her face.

"An excellent question, dear Watson! Black Mesa was one of the biggest research and development companies back in the 2000s. They were working on government contracts in a variety of fields including rocketry, theoretical physics, experimental propulsion, robotics, hydroelectricity, and applied mathematics among other things. Before the Beilan Island Incident, they were competing with their rivals of Aperture Science for grant money and contracts especially when both delved into experiments involving teleportation."

"Teleportation?" Thompson asked with a raised eyebrow, "Hard to believe that would've got anywhere with that."

Persica turned towards her and wagged her finger at the T-Doll as if scolding a child,

"On the contrary, Black Mesa made a hell of a lot of progress into Quantum Displacement in fact a few years before the Beilan Island Incident they showed off several working prototypes! Can you imagine what Griffon & Kryuger could do with that? We could hit them with surprise hit and run attacks from inside their territory and they wouldn't even know what hit them!"

The scientist zipped back to her laptop as she began working on her laptop again. As Thompson thought about what the doctor had said, the idea of ambushing and scaring the hell out of Sangvis Ferri appealed to her and it could also give her fellow T-Dolls and allies in G&K a significant advantage against SF. Hell, maybe it could even help end the war against them faster than originally thought! Though part of her wondered...if Black Mesa had the technology for working teleportation...what else were they working on?

"Another excellent question, Thompson."

Wait, did ask that question out loud? Oops.

"Like I said they had a number of government contracts into research & development and it's no secret that Black Mesa had a number of contracts assigned by our allies in the United States especially in one field in particular."

"What field would that be?" Thompson asked.

She immediately regretted asking that question as Persica's grin grew larger and much more...twisted when she answered;

"Weapons Development."

* * *

 _A few months later..._

Even though Helian had gotten use to Persica's antics especially while working at both 16Labs and IOP...she couldn't help but feel a small amount of dread when the doctor offered to help her in an ongoing mission to defend a populated area from Sangvis Ferri forces.

She was used to her offering new equipment for their forces...for a small price that is but for her to come to a command post in person was unusual. Helian massaged her temple, she felt a headache coming on. Something told her that she was going to have a hell of a lot of paperwork to complete after Persica finished her surprise visit...

Suddenly, she heard a door slide open as a familiar face came into the room as Helian observed the holographic map below her. Speak of the devil and they will appear, she supposed. Persica came in casually before grabbing an unused office chair, claiming it and then sliding next to her.

"May I dare ask why you're here?" Helian asked with a sigh.

Persica gave her a faux-offended look. "Oh, Dear Helian, what's wrong with visiting an old friend I mean we all work together for the same cause. Am I right?" She asked in an almost sing-song voice.

Helian wished she had some painkillers right now.

"Look, I got several echelons trying to keep these Sangvis Ferri units from breaking into the city so unless there is an important reason why you're here I'd like to ask you to leave."

Persica cleared her throat. "Business as usual, eh? Alright, the reason I came by here was to offer you a helping hand in this battle."

Helian raised an eyebrow before asking; "How so?"

Persica gave her a small mischievous grin.

"Remember how I helped the US Military and our own forces reclaim Black Mesa?"

Helian nodded with a hum of acknowledgement.

"Yeah, well I managed to access their old servers and I backed up a hell of a lot of data for the US Military including a hell of a lot of information on some of their research projects before the Beilan Island Incident hit. However, I also kept a copy of all of that information for myself so I could comb through it all and I managed to find some of their old projects that were worth looking into."

Helian seemed intrigued rather than upset, though a part of her told her not to keep her hopes up just in case.

"So, can I assume you've managed to reverse-engineer some of their technology?"

At that point Persica sighed and slouched a bit in her chair.

"Yes and no. There were several projects that we could've theoretically replicated in lab conditions but unfortunately IOP wouldn't be able to squeeze all of them into their budget despite how much of an advantage it would've given us. In particular anything involving Quantum Displacement, I.E: Teleportation are off the table until we have a better idea of what it's going to cost. Not to mention there is a lot more to it than I originally had thought."

"How so?" Helian asked.

Persica leaned back into the chair with her hands behind her head.

"Well, apparently the scientists at Black Mesa found some sort of...parallel dimension involved with the teleportation process...one of which had flora and fauna unlike anything we have here on Earth. I'm still combing through of all the information but IOP doesn't want to risk funding any experiments or projects involving teleportation until we know for sure that the process is safe."

"I'm sorry to hear that, doctor."

Persica grinned again.

"No need to apologize because on the bright side though we did manage to find information on some of the experimental weapons they've been developing...in fact we managed to replicate one of them recently."  
Helian nodded, "Well, congratulations I look forward to seeing it in acti-"

Helian paused for a moment.

"Wait...exactly when did you replicate it?" Helian asked

Persica grinned.

"About four...maybe five weeks ago."

"Is it ready for deployment?" Helian asked.

Persica's grin grew a little wider.

"All I need is your permission and we can do a test run here."

Helian paled for a moment before shaking her head.

"Can you guarantee that it will not cause any collateral damage?" Helian asked with a glare.

Persica waved her hand in front of her face,

"Relax, it's a handheld weapon...no bigger than a rifle and I've got someone who's trained in how to use it."

Helian clicked her tongue.

"Permission denied, I am not taking the risk of having one of our men or women lose their life out there."

Helian was about to reprimand the doctor but then she noticed she was still smiling.

"Whoever said that a human was wielding it?" Persica asked.

Helian wanted nothing more to give the doctor a piece of her mi-

She paused. If the wielder wasn't human, then that meant...

"You mean...you..."

Persica's grin remained in place.

"Yep."

Helian sighed to herself, massaging her temples.

"Permission granted...Just minimize the collateral damage if you can."

Persica shrugged,

"No promises." She pulled her phone out before tapping a button on touch screen.

"Hey, it's Persica...You're good to go!"

She then pressed the button again before turning back to the holographic map in front of her as Helian groaned under her breath.

"Hey Helian, want to watch the fireworks?" Persica asked.

"...If I must." Helian mumbled before coming over.

She watched as the holographic representation of a helicopter appeared, this one featuring a marker over top with the insignia of 16Labs before another marker pinged and appeared below it, a sign that a T-doll had arrived into the combat zone.

* * *

"Suppressive Fire!"

"Fire in the Hole!"

"I need backup!"

"Watch that crossfire!"

Super SASS grimaced as the voices of fellow T-Dolls came from in front of her as the staccato of gun fire rang out from her allies.

"SASS, I got a sniper in the hardware store to your left!" Shouted her spotter and fellow T-Doll Grizzly MKV

"I see them." SASS muttered as she centered the targeting reticulated on her scope on her target; a Jaeger marksmen T-Doll of Sangvis Ferri pinning down two of her allies. She inhaled, focused on her target's head, and then...

 **BANG!**

The enemy T-doll flew backwards out of sight, dead.

"We got an artillery unit coming in from the skyscraper to your right!" Shouted Grizzly.

"I got my eyes on them." Super SASS muttered as she lined up her next shot with a Jaguar; a quadrupedal wheeled vehicle with a mortar launcher for a turret.

She focused on the mortar launcher as it warmed up, giving a few of her allies a warning to scatter and find new cover. Once again, she focused on her target, inhaled...

 **BANG!**

Then exhaled.

Grizzly sighed to herself.

"Alright that should be the last of th-"

She was interrupted when she saw a massive quadrupedal mechanical unit, this one much larger than the Jaguar followed by smaller almost canine dinergate robots.

"Shit, we got a heavy unit!"

Super SASS wheeled around, seeing the machine preparing to take a shot at the vulnerable T-dolls falling back to higher ground but then there was a hissing buzz in the air and a orange beam punched through one of its legs.

"What the hell was that?" Grizzly asked.

Super SASS heard it again and turned to her right, peering out of cover to see who had taken that shot and to her surprise it wasn't a G&K T-Doll...or at least one she's ever seen before.

Much like other T-Dolls in use by G&K, the T-Doll was of the female persuasion with a wiry build and orange hair tied into a bushy brown ponytail. She wore a pair of safety goggles over her eyes, khaki pants, dress shoes, a blue button-up shirt, and a lab coat although oddly she also had elbow-pads and kneepads on as well. Her weapon...was odd to say the least. It looked like or at least resembled a rifle of some sort, however the copper nozzle-shaped working end of the weapon was protruding in front of it via a set of copper rods that went from the top and looped into the main body, a black hose went from the nozzle into the main body more specifically into a chassis that had copper wires coiled into a torus. There was a handle on the left side of the body and above that was a set of batteries wired into the coils in front of them while behind both was a rounded capacitor that gave a dull blue glow. Finally trailing off to the back was a simple metallic stock.

The T-doll wielding it had a bit of cautious curiosity in her grey eyes as she observed the damage done to Sangvis Ferri's heavy unit. The mechanical monstrosity though crippled raised its head up to peer at whoever dared to fire at it before preparing a firing solution. By that time though, the T-Doll in scientist-like garbs was already on the run, strafing to the right as the capacitor spun and the weapon whirred to life with faint crackles of orange energy around it. She fired again, this time aiming for its other leg, crippling it again but that didn't stop it from firing a few rockets at her. The T-Doll slid to the ground underneath the explosive projectiles trailing above her and fired several quick semi-automatic bursts at the machines dinergate escorts, tearing through them with orange energy blasts.

With one final charge, she sped forward as the capacitor spun again though this time, she held the impending blast longer until the gun was nearly burning in her arms before firing one powerful blast that almost sent her backwards from the recoil. The blast destroyed the head of the machine, killing it for good.

She lowered her weapon, pulling her safety goggles up to observe the damage, she squinted and took a closer look at its remains before nodding and turning back towards the area occupied by her allies, some of whom were watching her with jaws dropped in amazement.

"Ah," She said bashfully as she scratched the back of her head.

"Greetings, I am XVL1456 though you can call me Tau for short. It's a pleasure to meet all of you." she said.

Immediately, some of the younger-looking T-Dolls ran towards her and bombarding her with questions, much to Tau's bemusement.

Grizzly however chuckled.

"The new girl's pretty interesting, don't ya think?" Grizzly asked her companion.

Super SASS hummed in agreement with a short nod.

* * *

"So? What do you think?" Persica asked Helian who looked impressed with the demonstration.

Straight to the point, Helian only asked her one question; "How long until we can produce more of them?"

Persica had a grin on her face as she tossed a file folder in front of her.

"As soon as you sign these."

Helian raised a brow before grabbing a pen from one of her pockets as she began jotting down her signature on various forms a part of her wondered what the other commanders would think of this new development.

* * *

 **And that's the end, folks!**

 **The idea for this story came to me after I saw that there was a lack of _Girls Frontline_ crossovers on this site, especially considering ****the fact it's had English-Language Support since 2018. So I decided to rectify the situation by writing up a crossover, the first I had in mind was a multi-chapter crossover with** _ **Evangelion**_ **but I wasn't done drafting the plot so I decided to put to finish that first and then post the prologue. However, I was inspired to write this after I found out that the 20th Anniversary of _Half-Life_ was coming up so I decided to write this.  
**

 **Unfortunately, work on this story was delayed because I was bogged down by coursework but with all that out of the way (for the moment) I've finally managed to finish it. I have an idea for a similar crossover that I'll write up in the future but for now I hope you all enjoyed reading this little crossover short I came up with.**

 **Cheers,**

 **-VentXekart**

 **PS: On a different note, I'm fucking hyped for the upcoming Xen Update for _Black Mesa_!**

 **UPDATE 10/14/2019: Fixed some grammatical and spelling errors.**


End file.
